6l8e

Crystal structure of heterohexameric YoeB-YefM complex bound to 26bp-DNA

spinqualitylabelsall models 6l8e, resolution 2.35Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6l8e is a 16 chain structure with sequence from Staphylococcus aureus subsp. aureus NCTC 8325 and Synthetic construct. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.35Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q2G285_STAA8 Antitoxin component of a type II toxin-antitoxin (TA) system.[RuleBase:RU362080] Publication Abstract from PubMed YoeB-YefM, the widespread type II toxin-antitoxin (TA) module, binds to its own promoter to autoregulate its transcription: repress or induce transcription under normal or stress conditions, respectively. It remains unclear how YoeB-YefM regulates its transcription depending on the YoeB to YefM TA ratio. We find that YoeB-YefM complex from S.aureus exists as two distinct oligomeric assemblies: heterotetramer (YoeB-YefM2-YoeB) and heterohexamer (YoeB-YefM2-YefM2-YoeB) with low and high DNA-binding affinities, respectively. Structures of the heterotetramer alone and heterohexamer bound to promoter DNA reveals that YefM C-terminal domain undergoes disorder to order transition upon YoeB binding, which allosterically affects the conformation of N-terminal DNA-binding domain. At TA ratio of 1:2, unsaturated binding of YoeB to the C-terminal regions of YefM dimer forms an optimal heterohexamer for DNA binding, and two YefM dimers with N-terminal domains dock into the adjacent major grooves of DNA to specifically recognize the 5'-TTGTACAN6AGTACAA-3' palindromic sequence, resulting in transcriptional repression. In contrast, at TA ratio of 1:1, binding of two additional YoeB molecules onto the heterohexamer induces the completely ordered conformation of YefM and disassembles the heterohexamer into two heterotetramers, which are unable to bind the promoter DNA optimally due to steric clashes, hence derepresses TA operon transcription. Distinct oligomeric structures of the YoeB-YefM complex provide insights into the conditional cooperativity of type II toxin-antitoxin system.,Xue L, Yue J, Ke J, Khan MH, Wen W, Sun B, Zhu Z, Niu L Nucleic Acids Res. 2020 Aug 26. pii: 5897335. doi: 10.1093/nar/gkaa706. PMID:32845304 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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